At the end of the third quarter of 2013, Russian companies' free float stood at $213 billion, including $121 billion of foreign investors' money, according to the FactSet research agency.

Some $29 billion worth of stocks are owned by Russian banks, pension funds and insurance companies, with a further $1 billion, according to Investfunds.ru, owned by Russian mutual funds.

Private Russian investors own some 10 percent of free-floating shares, analysts believe. The remaining free float ($42 billion) is divided 1:2 between foreign hedge funds and Russian funds, which do not disclose information about themselves.

One third of investors active in Russia are U.S. funds; another third are funds from continental Europe; and the remaining third are U.K. funds. The biggest foreign investor (more than $5 billion) has turned out to be the Norwegian Government Pension Fund, followed by Vanguard Emerging Markets Stock Index Fund (about $4.7 billion) and the Oppenheimer fund (with slightly less than $3 billion invested in Russian stocks).

Before the 2008-2009 crisis, foreign investors owned about 60 percent of free-floating Russian shares.

Experts believe that the fact that a large share of the Russian stock market belongs to foreign investors is a positive sign. It shows that the market is growing. Although at the same time it creates risks of a sudden capital flight.

A rising share of foreign-owned free float of Russian companies is a consequence not only of an increase in foreign investment, but of a drop in Russian players' investment. The Kommersant daily estimated, based on Investfunds.ru data, that since the start of 2009, Russian investors have withdrawn nearly $750 million from mutual funds.

Simargl Capital director Dmitri Sadovy said that Russian investors have still not overcome the fear caused by the 2008-2009 crash and are therefore reluctant to invest in shares.

Their passivity allows non-residents to have such a strong sway over Russian stock market dynamics.

"To have a significant influence, domestic investors should own at least 50 percent of the total free float," Sadovy said.

Based on materials from Kommersant and Vedomosti